Petroleum-tank attachment



A ril 15', 1924; 1,490,782

J. H. M'ILLIGAN PETROLEUM TANK ATTACHMENT Filed 001;. so 1922 iii 424 71 7 INVENTOR.

All ORNEY.

katented Apr. 15, 1924.

UNITED STATES 1;490,7s2 PATENT orrica.

JAMES H. MILLIGAN, OF LOS ANGELFS, CALIFORNIA.

PETROLEUM-TANK ATTACHMENT.

Application filed October 80, 1922. Serial No. 598,041.

Los Angeles, in the county of Los Angeles and the State of California, have invented certain new and useful Improvements in Petroleum-Tank Attachments, of which the following is a specification.

This invention has reference to a petroleum tank attachment wherein the tank is employed for the storage of crude petroleum before being refined, or for other purposes. The stock and storage tanksfor petroleum are subject to large and constant losses of oil through evaporation. Just What this loss amounts to in any given lease has never been accurately determined and the only present, easily practical, method of determining this loss is by gaging the tank.

The average stock tank may be usually assumed-to be of two hundred and fifty bar rels capacity, approximatin fifteen feet in diameter by eight feet in helght. In such a tank the loss by evaporation makes it, by gaging the tank, usually much more than one inch of oil per day, and in the case of 1i ht crudes, or hghter, and rich in gasolenes, t is loss may amount oftentimes to three or four inches per day.

Serious losses measure into dollars and cents and may represent two to two and a half barrels per day from the average storage tank, or, in a percentage of volume, of one per cent to four or cent. a day based on a. tank full of oil. nasmuch as the exposed surface is the same whether the tank be full or but partly full, the percentage of volume lost is really much greater. In other words if the loss by evaporation from a tank full of oil be one per cent, then from a tank half filled the loss will be two per cent and the loss from a tank with but two feet of oil in it based on the volume of oil in the tank, will be still greater, nor is this by any means the total loss. To determine accurately what the total loss of oil on the lease may be from the well head to the pipe,

line would require accurately metering of the oil as it comes from the ground.

In accordance with the invention the storage tank is provided with a salt water or brine cooled vapor-condensing system including a tubular member with a vapor chamber and water jacket. The outer or water jacket is of heavy steel or cast iron covered with cork or other insulating material to keep out the heat. The inner or vapor chamber is of sheet copper, very thin, to insure instant condensation At the top of the vapor chamber there is located a relief or intake valve. This valve is set to relieve wild ases that come into the tank from the pipe ine, to escape at approximatel ten pounds pressure. The intake valve 1s set at one pound vacuum per square inch. The valve is of bronze without springs or adjusting to insure relief at all times under proper pressure without sticking.

. The salt water or heavy brine is cooled to about fourteen degrees temperature by a suitable ammonia freezing syflem and the.

brine is fed through cork-covered pipes to and through condensers located at i that point, thereby assuring perfect condensation for all the condensers.

Salt water is employed because of its nonfreezing character, allowing it to be used in all climates successfully.

- The action of the condensing system is to .condense the va ors that rise from oil stored in airtight tan and same gravity of oil as when pumped from the ground. v

- The vapors when condensing adhere to the inner sides of the cooling'chamber and run down the inside and drip back into the oil tank.

As fast as the vapors rise the are condensed back into liquid form an therefore there can be no vapor on the relief valve at any time. All wild gases accumulate in the tank at the relief valve when the pressure reaches approximately ten pounds per square inch, or according to the pressure the relief valve is set for.

The invention will be best understood from a consideration of the following detailed description, taken in connection with the accompanying drawings forming part of this specification, with the understanding that the invention is not confined to any strict conformity to the showing of the drawings but may be changed and modified so long as such changes and modifications mark no material departure from the salient features of the invention as expressed in the appended claims.

In the drawings':-

Fig. 1 is a side elevation of the upper portion of a storage tank with the condensing system attached.

Fig. 2 is an enlarged view of the condensing system at the apex or dome of the. tank.

Referring to the drawings there is shown a tank 1 such as is usually employed for the storage of petroleum. This tank is usually provided with a crown or' dome portion 2 in which accumulating gases are naturally gathered. I Y

Erected on the apex of the dome 2 is a condenser 3 communicating at the lower end with the interior of the tank and at the upper end provided with a valve 4 set to dis charge at a moderate pressure, 'say at about ten pounds per square inch.

Surrounding the condenser chamber 3, is a jacket 5 spaced from the condenser 3 to contain a quantity 6 of brine or salt Water fed into the jacket 5 by means of a pipe 7, and also provided with an insulating jacket 8 coming from a salt water cooling system, not shown in the drawings, but which may follow the usual ractice in freezing machines. The pipe enters the'jacket 5 near the lower end thereof above the crown 20f the tank 1 and leavesthe upper end of the salt water container 5 by the way of another ipe 9 returnin 'to the freezing machine also incased in insulating material.

The tank 1 is furnished with a ladder 10 at one side whereby access to the top of the tank is provided, and the tank also is furnished with a removable pressure manhole 11.

Having thus described the invention, what isclaimed is L-A storage tank for condensable gases occurrin therein, comprising a container for the con ensable gases, and a means for retaining a circulating refrigerant in contact with said container, located at a high point with respect to the storage tank, to there chill and condense the gases.

2. A storage tank for condensable gases .occurring therein, comprising a container for 'the tank and provided with a relief vValve and a duct for a refrigerant surrounding the container above the storage'tank.

4. A storage tank for condensable gases occurring therein, comprising a container for the condensable gases rismg from the top of the tank and provided with a relief valve and a duct for a refrigerant surrounding the container above the storage tank, said duct having a heat insulating covering.

5. A storagetank for condensable gases occurring therein, comprising a. container for the condensable gases rising from the top of the tank and provided with a relief valve and a duct for a refrigerant surrounding the container above the storage tank, said duct having a heat insulating covering, said container communicating with an incoming duct for the refrigerant at a low;

point and with an outgoingduct for the refrigerant at a high point.

6. A storage'tank for condensable gases occurring therein, comprising a container for the condensable gases rising from the top of the tank and provided with a -relief valve and a ductfor a refrigerant surrounding the container above the storage tank, said duct having a heat insulating covering, said container communicating with an incoming duct for the refrigerant at.

a low point and with an outgoing duct for the refrigerant at a high point, the refrigerant container and the duct leading to and from it having an exterior heat insulating envelope and an interior covering of thin heat conducting material.

In testimony whereof, I aflix my signature hereto.

JAMES H. MILLIGAN 

